"If only I could create something, if God had given me this gift, I would find unlimited pleasure in doing so. But, alas, I must content myself with enjoying the admiration I have for the creations of others, of which your works are a part," ignites Paul Rosenberg (1881– 1959) in a letter sent to Matisse. Paul Rosenberg began to work with his brother. Léonce Rosenberg in the gallery of their father, who emigrated from Slovakia to Paris in 1878, is one of the first to bet on the Impressionists. When he died in 1906, they took over the business located on avenue de l'Opéra, but separated four years later and founded their galleries. Paul settles in a chic Haussmannian building at 21, rue La Boétie, in the 8th arrondissement, where he focuses on the Impressionists and the Barbizon school. Léonce, opened the modern Effort gallery near that of his brother, at 19, rue de La Baume. He recovers the cubists Picasso and Braque, discovered by Daniel-Henry Kahnweiler, an unhappy visionary merchant who, because of his German nationality, saw in 1914 his gallery placed in sequestration as property belonging to the enemy. Léonce will even be the expert in the auction of Kahnweiler's goods, organized in June 1921 in Drouot, which the profession will never forgive him. The episode is famous: furious to see his canvases sold out on the day of the sale, Braque will throw himself on Léonce and kick his buttocks. The great rival Kahnweiler discarded. Léonce in difficulty, the situation benefits Paul, known for his seriousness and his keen eye. His business prospered thanks to the sale of 19th-century masters. Still, he became more and more interested in contemporary artists, without however pushing the boundaries of the pictorial field too far - the door of his gallery thus remained closed to the surrealists. Marie Laurencin was the first to integrate 21, rue La Boétie in 1913, followed by Picasso five years later. Rosenberg admires Picasso. Without restraint. He considers him "the greatest painter of the present times", hails his capacity to renew himself each year to go "always beyond his limits". Between the two men was born a solid friendship, coupled with fruitful professional cooperation. Picasso calls him "my dear Rosi", the merchant gives him "my dear Pic" or "my dear Casso". He offered to move him to 23, rue La Boétie with his wife, the dancer Olga Khokhlova. From the windows of his apartment, the artist can directly show the merchant his latest productions. Aware of fashionable tastes, Rosenberg encouraged him to distance himself from Cubism in favor of a certain "return to order". The first Picasso exhibition, in 1919, revealed 167 drawings: no cubism, but harlequins, scenes from the circus, ballet, or bullfight. The rating of the Spanish painter soars. And soon, it was Georges Braque (1924), then Fernand Léger (1927), who joined the gallery. For "his" artists, Paul Rosenberg draws up contracts called "first sight", granting them a generous annual sum in exchange for the scoop on the choice of works, a judicious technique to keep the lion's share without restricting the artist. He shows himself more and more confident, demanding, passionate. His friend and colleague Alfred Daber said that "his body started to shiver like an impatient child when he saw a work he coveted. The shaking did not stop until he had obtained the painting". "To say that he was aware of his instinct. It is an understatement, adds Anne Sinclair. He had a great idea of ​​his talent, the importance of his house, the unique quality of the works displayed in his gallery, or that of the catalogs published by him for his exhibitions. He knows that the moderns are not to everyone's taste. So, he tempers their passion by exposing them in a luxurious decor of marble and onyx - the painter Jacques-Émile Blanche will describe the gallery as "a Ritz-Palace of avant-garde art". On the ground floor, visitors are confronted with the latest art trends, but if they are too timid, Rosenberg takes them to the mezzanine where they meet Delacroix, Ingres, Corot, Courbet, Gauguin, Monet, Manet. He chooses to sell the Impressionists to live "and be able to afford to wait until the desire comes to the amateurs to acquire the contemporary painting which was dear to him", specifies Anne Sinclair. Her grandfather bet on the positive values ​​of the XIXth century to value the young guard of the XXth century. Winning strategy: success is there. The exhibitions follow one another at a frenetic pace. In the first half of 1936 alone, the gallery presented works by Braque, Seurat, Picasso, Monet, and Matisse. Until then, fiercely independent, Matisse finally joined 21, rue La Boétie to take advantage of the stable network that Paul Rosenberg built in Europe and across the Atlantic. Because the merchant very early understood the importance of the American market, traveling through the United States to advise museum curators or business people. Dr. Barnes, the Claribel & Etta Cone sisters, the banker Chester Dale.The biggest collectors are in his address book. In 1934, he organized the legendary exhibition "Braque, Matisse and Picasso" in New York and, in 1936, opened a branch in London with his brother-in-law, the Parisian antique dealer Jacques Helft. The assassin lives at 21 The Second World War put a brutal brake on its activities. In March 1939, he had to close his Paris gallery; and takes refuge in the fall with his family in Floirac, not far from Bordeaux. He manages to put some of his paintings safety, some in Tours in a depot in the name of his driver Louis Le Gall, and a set of 162 paintings (fifteen Matisse and Van Gogh, Cézanne, Monet, Gauguin , Picasso) in a safe at the Libourne bank. With the help of his friend Alfred Barr , director of New York's MoMA, Paul and his family managed to reach the United States in September 1940; all, except his son Alexandre and his two cousins ​​who left to join General de Gaulle in London. He opened a new gallery in New York in 1941, at 79 East 57th Street, where he organized exhibitions for the benefit of the Free French Forces. He is homesick, worried about his son, but has no idea of ​​the ongoing tragedy. However, on February 23, 1942, a decree pronounced his forfeiture of nationality, a procedure that preceded the deportation. The (bad) news comes to him little by little. After landing in July 1940 at 21, rue La Boétie, the Nazis, who embarked on a vast plan of looting of art collections belonging to the Jews, requested his gallery to welcome the ignominious Institute for the Study of Jewish Questions in May 1941. Four months later, they will get their hands on the paintings kept in Libourne while the house of Floirac will be ransacked on denunciation by two Parisian merchants - Yves Perdoux and Count de Lestang -, hoping to get a share of the booty. After the Allied victory, the restitution of his property will be a long struggle, won (in large part at least) thanks to his pugnacity - the meticulous inventory he had made of his works was of great help to him -, to the testimony of his artist friends and the Artistic Recovery Commission created by the resistant Rose Valland. Without forgetting breathtaking circumstances. Like that day in August 1944, when his son Alexandre discovers inside a German convoy that he had just arrested with his comrades dozens of cases of works of art containing the paintings at 21, rue La Boétie! The story will even inspire a movie : the Train , with Burt Lancaster and Jeanne Moreau. Rosenberg was robbed of nearly 400 paintings. About sixty were never found, the others were recovered and sold from the New York gallery, or donated to museums. The family keeps a few, including those of Anne Sinclair, exhibited at the Maillol museum. After the death of Paul Rosenberg, the restitutions continued. Still very recently, in 2012, his heirs spotted in an exhibition at the Center Pompidou a Blue profile in front of the fireplace (1937) by Matisse, rendered two years later by the Norwegian museum Henie Onstad. Beaux arts magazine